Question

I’ve started learning Rails recently and have completed the sample app at http://ruby.railstutorial.org. I am trying to add user-created groups to the sample social network. I’ve gotten stuck at how exactly I should model the group. I know there should be a user_id of who owns the group and there should be strings of the name and description. Aside from that I have no idea what the rest of the group data model should look like. Thank you in advance.

Answer 1

If you want a user to be in multiple groups your relations should be something like this

class Group < ActiveRecord::Base
  belongs_to :owner, :class_name => "User"
  has_many :memberships
  has_many :members, :through => :memberships
end

class Membership < ActiveRecord::Base
  belongs_to :member, :class_name => "User" 
  belongs_to :group
end

class User < ActiveRecord::Base
  has_many :memberships
  has_many :groups, :through => :memberships
  has_many :owned_groups, :class_name => "Group", :foreign_key => "owner_id"
end